1. Field of the Invention
The present invention relates to a disc apparatus which extracts a tray from a tray accommodating section such as a magazine and attaches a disc on this tray to a disc drive section.
2. Description of the Related Art
FIGS. 10A and 10B are side views showing the operation of a conventional disc apparatus.
In this disc apparatus, a plurality of trays T are provided in a magazine M loaded in the apparatus so as to be capable of being drawn out, and a disc D is placed on each tray T. A disc drive section 1 opposed to the loading position of the magazine M is provided with a drive chassis 2 and a clamp arm 5 rotatably supported by the drive chassis 2 through the intermediation of a shaft 7.
The drive chassis 2 carries a turntable 3, a spindle motor 4 for turning the turntable 3, and an optical head. A clamper 6 is rotatably supported by the clamp arm 5.
In this disc apparatus, one of the trays T in the magazine M is selected through vertical movement as seen in the drawing of the disc drive section 1. As shown in FIG. 10A, in the condition in which the disc drive section 1 is at rest at a position where it has selected a tray, the clamp arm 5 rotates upward and the clamper 6 is separated from the turntable 3. In this condition, the tray T selected from the magazine M is drawn out toward the disc drive section 1. When the tray T is drawn out and the center of the disc D on the tray T is matched with the turntable 3, the clamp arm 5 rotates downward, and the central portion of the disc D is clamped by the clamper 6 and the turntable 3. After this, as shown in FIG. 10B, the tray T is returned to the magazine M, and the disc D is driven by the spindle motor 4, whereby information recorded fin on the disc D is read by the optical head.
When the driving of the disc D has been completed, the empty tray T is drawn out over the disc drive section 1 again, and, when the tray T reaches a position under the disc D, the clamp arm 5 is raised and the clamper 6 is separated from the disc D, and the clamping of the disc D is canceled, the free disc D being placed on the tray T. Then, the tray T is returned to the magazine M with the disc D.
When constructing the disc apparatus as shown in FIGS. 10(A) and 10(B), however, the following problems are involved.
(1) In the operation of drawing out the tray T accommodated in the magazine M toward the disc drive section 1, a tray transfer member engaged with the tray T is moved in the drawing direction by using the power of a motor or the like. When, as shown in FIG. 10B, the tray T is drawn out and the central portion of the disc D on the tray T is matched with the turntable 3, it is necessary to detect the drawn-out position of the tray T and stop the operation of drawing out the tray T. When it is detected that the tray T has been drawn out through a predetermined distance, the clamp arm 5 is lowered, and then the tray T is returned to the magazine M.
In this system, it is necessary to provide a detecting means such as a switch for detecting that the tray T has been drawn out through a predetermined distance from the magazine, so that the number of parts is rather large. Further, it is necessary to control the starting and stopping of the motor for operating the tray transfer member in relationship with the detection output, so that the control on the electronic circuit is complicated.
Furthermore, due to positional deviation of the detecting means, deviation in the detection timing of the detecting means such as a switch, etc., there is a possibility of positional deviation occurring in the position at which the drawing of the tray T out of the magazine M is completed. When such positional deviation occurs, the positioning of the center of the disc D on the turntable 3 cannot be correctly effected, and there is a danger of deficient clamping occurring.
(2) Conventionally, a driving means for raising and lowering the clamp arm 5 has been provided separately from the driving means for drawing out the tray T, so that the number of driving sources such as motors is rather large, making it difficult to achieve a reduction in the size of the apparatus. Further, it is difficult to set the timing between the completion of the operation of drawing out the tray T and the lowering of the clamp arm 5, with the result that it is necessary to perform a fine adjusting operation in the production process, resulting in an increase in production man-hours.
(3) In the case of an in-car apparatus, the disc driving section 1 is supported by an elastic support member such as an oil damper or a spring so that the influence of the vibration of the vehicle may be lessened. However, when, as shown in FIG. 10A, the tray T is drawn out, it is necessary to lock the disc driving section 1 in order to match the center of the disc D with the turntable 3. When this locking is effected by using still another drive source, the number of drive source is increased. Further, the setting of the operation timing is complicated.
(4) The operation of drawing the tray T out of the magazine M is made possible by engaging a hook with the tray T and drawing out the tray T with the hook. However, when drawing out the tray T with the hook, the tray T is subject to vertical play. In view of this, it has conventionally been necessary to provide guide members for guiding both sides of the tray T, resulting in a complicated construction.